Adjust The Fps On An Airsoft

Adjust the FPS on an Airsoft

Adjusting an airsoft gun’s feet per second (FPS) is the greatest way to hit a far target. The best way to do this is replacing the spring, barrel, gearbox and motor. Upgrading the barrel to a small-diameter one will improve accuracy and FPS. An improved spring will push the piston harder, which also increases FPS. The airsoft gun’s motor can be upgraded to handle the newer spring, which ensures maximum spring compression. The gearbox needs to be upgraded when the motor or spring is upgraded to prevent damage to the internal gears.


1. Remove the magazine from the gun. Fire the gun in auto mode three times to make certain there are no BBs in the chamber. Disconnect and remove the battery.

2. Unscrew the flat-head screw on the back of the stock.

3. Unscrew the Phillips screw down into the stock tube using a long screwdriver. The stock tube is attached to the gearbox.

4. Remove the two screws on the bottom of the hand grip using a Phillips-head screwdriver. Do not remove the hex key or screw in the middle of the hand grip; this is for adjusting the motor tension to the gearbox.

5. Remove the end plate from the hand grip. Be careful with the small metal shim inside the end plate as not to lose it; this is crucial to the operation and positioning of the gun’s motor.

6. Disconnect the black and red wires leads from the motor. Use caution when handling the wire connectors on the motor; they can be delicate.

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7. Slide out the motor of the hand grip.

8. Remove two screws inside the hand grip that hold it to the gearbox. Remove the hand grip.

9. Remove the release button and spring (underneath the button) for the BB magazine by using a small screwdriver.

10. Remove the back body pin on the receiver. Remove the front body pin and divide the lower and upper receiver–this will require some force; however, do not crack the tabs.

11. Remove the gearbox.

12. Remove the barrel by sliding it out and unscrew the four screws that hold the receiver assembly and outer barrel and together.

13. Remove the outer barrel from the receiver.

14. Separate the inner and outer barrels.

15. Take off the clip from the barrels hop-up unit with needle-nose pliers.

16. Carefully remove the barrel from the hop-up unit.

17.Remove the hop-up bucking from the barrel. Replace with the new barrel.

18. Reverse the steps above to put the airsoft gun back together. When assembling the gun, install the new gearbox and motor.